Depends what you are looking for because the Sukhumvit area vs. Ploenchit are totally different . Ren is close to some of the best malls and is a very short walk to BTS. JW is closer to the nightlife and available companions.

As a Gold you will definitely get Lounge access and I find it one of the best lounges anywhere in the world. IMHO

Been awhile since I have been in JW so I 'm not sure whether there rooms have been upgraded to the level of the Ren. Love the big deep bathtub and the very strong shower. Remember there is a switch in bathroom to lower privacy curtain since there is a glass wall into the bathroom.